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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 | /* This has so very few changes over libgcc2's __udivmoddi4 it isn't funny. */ #include <math-emu/soft-fp.h> #undef count_leading_zeros #define count_leading_zeros __FP_CLZ void _fp_udivmodti4(_FP_W_TYPE q[2], _FP_W_TYPE r[2], _FP_W_TYPE n1, _FP_W_TYPE n0, _FP_W_TYPE d1, _FP_W_TYPE d0) { _FP_W_TYPE q0, q1, r0, r1; _FP_I_TYPE b, bm; if (d1 == 0) { #if !UDIV_NEEDS_NORMALIZATION if (d0 > n1) { /* 0q = nn / 0D */ udiv_qrnnd (q0, n0, n1, n0, d0); q1 = 0; /* Remainder in n0. */ } else { /* qq = NN / 0d */ if (d0 == 0) d0 = 1 / d0; /* Divide intentionally by zero. */ udiv_qrnnd (q1, n1, 0, n1, d0); udiv_qrnnd (q0, n0, n1, n0, d0); /* Remainder in n0. */ } r0 = n0; r1 = 0; #else /* UDIV_NEEDS_NORMALIZATION */ if (d0 > n1) { /* 0q = nn / 0D */ count_leading_zeros (bm, d0); if (bm != 0) { /* Normalize, i.e. make the most significant bit of the denominator set. */ d0 = d0 << bm; n1 = (n1 << bm) | (n0 >> (_FP_W_TYPE_SIZE - bm)); n0 = n0 << bm; } udiv_qrnnd (q0, n0, n1, n0, d0); q1 = 0; /* Remainder in n0 >> bm. */ } else { /* qq = NN / 0d */ if (d0 == 0) d0 = 1 / d0; /* Divide intentionally by zero. */ count_leading_zeros (bm, d0); if (bm == 0) { /* From (n1 >= d0) /\ (the most significant bit of d0 is set), conclude (the most significant bit of n1 is set) /\ (the leading quotient digit q1 = 1). This special case is necessary, not an optimization. (Shifts counts of SI_TYPE_SIZE are undefined.) */ n1 -= d0; q1 = 1; } else { _FP_W_TYPE n2; /* Normalize. */ b = _FP_W_TYPE_SIZE - bm; d0 = d0 << bm; n2 = n1 >> b; n1 = (n1 << bm) | (n0 >> b); n0 = n0 << bm; udiv_qrnnd (q1, n1, n2, n1, d0); } /* n1 != d0... */ udiv_qrnnd (q0, n0, n1, n0, d0); /* Remainder in n0 >> bm. */ } r0 = n0 >> bm; r1 = 0; #endif /* UDIV_NEEDS_NORMALIZATION */ } else { if (d1 > n1) { /* 00 = nn / DD */ q0 = 0; q1 = 0; /* Remainder in n1n0. */ r0 = n0; r1 = n1; } else { /* 0q = NN / dd */ count_leading_zeros (bm, d1); if (bm == 0) { /* From (n1 >= d1) /\ (the most significant bit of d1 is set), conclude (the most significant bit of n1 is set) /\ (the quotient digit q0 = 0 or 1). This special case is necessary, not an optimization. */ /* The condition on the next line takes advantage of that n1 >= d1 (true due to program flow). */ if (n1 > d1 || n0 >= d0) { q0 = 1; sub_ddmmss (n1, n0, n1, n0, d1, d0); } else q0 = 0; q1 = 0; r0 = n0; r1 = n1; } else { _FP_W_TYPE m1, m0, n2; /* Normalize. */ b = _FP_W_TYPE_SIZE - bm; d1 = (d1 << bm) | (d0 >> b); d0 = d0 << bm; n2 = n1 >> b; n1 = (n1 << bm) | (n0 >> b); n0 = n0 << bm; udiv_qrnnd (q0, n1, n2, n1, d1); umul_ppmm (m1, m0, q0, d0); if (m1 > n1 || (m1 == n1 && m0 > n0)) { q0--; sub_ddmmss (m1, m0, m1, m0, d1, d0); } q1 = 0; /* Remainder in (n1n0 - m1m0) >> bm. */ sub_ddmmss (n1, n0, n1, n0, m1, m0); r0 = (n1 << b) | (n0 >> bm); r1 = n1 >> bm; } } } q[0] = q0; q[1] = q1; r[0] = r0, r[1] = r1; } |